The present invention relates to a cigarette inspection apparatus for detecting a quality defect in a filter cigarette.
The quality, especially the flavor and taste, of a cigarette is affected by a variety of factors, one of which is ventilation resistance of the cigarette. In the process of manufacturing cigarettes, therefore, in general, a predetermined number of cigarettes per lot are sampled, and the ventilation resistances of the sampled cigarettes are measured one by one by using, for example, a cigarette inspection apparatus (ventilation measuring apparatus) shown in FIG. 11. The measured values of the ventilation resistances are used for quality control of cigarettes.
The ventilation measuring apparatus shown in FIG. 11 comprises a container 1 having supporters 3a, 3b and 3c for supporting a cigarette C to be measured. Each supporter has a support ring and a support member made of a flexible material and disposed on the inner peripheral surface of the support ring. When negative pressure is applied to a suction chamber formed in the support ring, a cylindrical portion of the support member is pulled toward the support ring, so that a central hole is enlarged which is provided in a bulkhead of the support member formed integrally with the cylindrical portion. In this state, if a cigarette C is supplied into the container 1 from the upper end opening of the container 1, the cigarette C freely falls while being guided by guides 5 and 6, and passes through the central holes of the support members disposed in the supporters 3c, 3b and 3a sequentially, until the tip of the cigarette C is brought into contact with a stopper 7 located right under the supporter 3a. 
Next, the suction chamber is communicated with the atmosphere, so that diameters of the central holes of the support members are restored to their former sizes. This permits the three support members to airtightly hold the tip of a filter section F, boundary between the filter section F and a tobacco wrapping section T, and tip of the tobacco wrapping section T of the cigarette C, respectively. In the container 1, three airtight chambers 2a, 2b, and 2c are defined by the supporters 3a, 3b, and 3c, a shutter 4, and the cigarette C. Although not shown in the figure, the first airtight chamber 2a is connected to a decompressor through a flowmeter, whereas the first and second airtight chambers 2b and 2c are communicated with the atmosphere through flowmeters.
When the air in the first airtight chamber 2a is sucked out by the decompressor, the air in the second and third airtight chambers 2b and 2c flows into the cigarette C through the peripheral surfaces of the filter section F and the tobacco wrapping section T, flows through the cigarette C, and flows into the first airtight chamber 2a from the tip face of the filter section F. A flow rate Vc of the air discharged by suction from the first airtight chamber 2a and flow rates Vf and Vp of the air flowing into the cigarette C through the peripheral surfaces of the filter section F and the tobacco wrapping section T in the second and third airtight chambers 2b and 2c are measured by means of three respective flowmeters, and the ventilation resistances are determined based on the measured values Vc, Vf, and Vp. After the measurement, the stopper 7 retreats to a retreat position as shown in the figure, and the shutter 4 is opened. As a result, the cigarette C freely falls to be discharged from the container 1. Then, the stopper 7 is moved forward to a cigarette-holding position, and the shutter 4 is closed to prepare for the subsequent measurement.
The above-mentioned ventilation measuring apparatus is constructed with the intention of measuring the ventilation resistances of the cigarettes one by one, which cigarette are sampled in the cigarette manufacturing process and thus limited in number. For this reason, it is extremely difficult to measure the ventilation resistances by means of the ventilation measuring apparatus with respect to all the cigarettes that are manufactured in large quantities through the cigarette manufacturing process.
That is, the ventilation resistance measurement using a ventilation container includes, as mentioned before, the first step of introducing the cigarette into the container 1, the second step of discharging the air in the first airtight chamber by suction while measuring the flow rate of the air discharged from the first airtight chamber and the flow rates of the air flowing into the second and third airtight chambers, and the third step of ejecting the cigarette from the container 1. Thus, it takes time to run the measurement. In actuality, therefore, it is impossible to carry out such ventilation resistance measurement with respect to all the cigarettes, especially on-line in succession. Furthermore, the on-line measurement requires a cigarette carrier system for carrying cigarettes from the cigarette manufacturing process to the ventilation measuring apparatus, and a cigarette inspection apparatus including such a carrier system has a large-scale structure.
By the way, a notable wrapping defect can occur in the cigarette, which may bring about a great air leakage. In case of such a cigarette, a large amount of air flows out of the cigarette or flows thereinto through the wrapping-defective part during the measurement of the ventilation resistance, resulting in such a notable error in the measured value as to stultify the ventilation measurement itself. The ventilation resistance measurement using the ventilation measuring apparatus has a drawback that it requires a long time for measurement with respect to a cigarette having a notable wrapping defect.
An object of the present invention is to provide a cigarette inspection apparatus capable of easily detecting a notable quality defect in a cigarette.
Another object of the present invention is to provide a cigarette inspection apparatus capable of measuring ventilation resistance of a cigarette easily and accurately.
Further another object of the present invention is to provide a cigarette inspection apparatus capable of measuring ventilation resistances with respect to all cigarettes manufactured in a cigarette manufacturing process.
In order to achieve the above objects, a cigarette inspection apparatus according to the present invention comprises air-introducing means for introducing air into a filter cigarette from a first end of the filter cigarette, which is on a non-filter side of the cigarette, a first pressure transducer for detecting an air pressure on a side close to the first end of the filter cigarette, and quality-judging means for judging quality of the filter cigarette, based on the air pressure detected by the first pressure transducer.
The cigarette inspection apparatus of the present invention has been invented with a recognition that a pressure drop in a filter cigarette at the time of introducing air into the cigarette through the first end of the non-filter side thereof indicates an amount of air leakage corresponding to a cigarette quality, especially a wrapping defect in the cigarette. Therefore, the cigarette inspection apparatus is capable of judging easily the cigarette quality, more particularly a quality defect in the cigarette, based on the air pressure on the first end side of the filter cigarette. In other words, the pressure drop in the filter cigarette can be determined based on the air pressure on the first end side before the air introduction into the cigarette and the air pressure on the first end side at the time of the air introduction. Based on this pressure drop, the cigarette quality, especially a notable quality defect in the cigarette can be easily judged. It is preferable that the air pressure is detected in a state where a peripheral surface of the filter cigarette is open to the atmosphere. The air introduction into the cigarette and the detection of the air pressure can be realized with a simple structure, and it is relatively easy to incorporate an apparatus having such a structure into a cigarette manufacturing apparatus. Therefore, the cigarette inspection apparatus according to the present invention is suitable to perform a 100% inspection of the quality associated with the ventilation resistances of the cigarettes manufactured in the cigarette manufacturing process.
Preferably, the cigarette inspection apparatus according to the present invention further comprises a second pressure transducer for detecting an air pressure produced on a side close to a second end of a filter cigarette, which is a filter side of the cigarette, due to the air introduced into the cigarette, and the quality-judging means has measuring means for determining the ventilation resistance of the filter cigarette, based on a difference between the air pressures detected by the first and second pressure transducers, respectively, and judges the quality of the filter cigarette based on the ventilation resistance.
The cigarette inspection apparatus according to this preferred embodiment is designed to judge the cigarette quality, based on an air pressure difference between both the ends of a filter cigarette, which accurately represents the pressure drop in the cigarette caused with the air introduction into the cigarette, and is hence excellent in accuracy of the cigarette quality judgement. It is preferable that the air pressure detection is performed in a state where the peripheral surface of the filter cigarette is open. The cigarette inspection apparatus is simple in structures for introducing air into the cigarette and for detecting the difference in the air pressure, and is hence suitable for incorporation into the cigarette manufacturing apparatus and for the 100% inspection of cigarettes.
Preferably, the air-introducing means comprises a first passage member having an air passage with an air outlet for discharging air supplied from an air source, the first passage member being disposed for abutment with a first end face of a filter cigarette, which is on the non-filter side of the cigarette, and pressure means for pressing a second end face of the filter cigarette, which is on the filter side of the cigarette, in an axial direction to make the first end face of the filter cigarette connected to the air outlet of the first passage member. The first pressure transducer is connected to the air passage of the first passage member.
According to this preferred embodiment, it is possible to surely introduce air to the non-filter side end face of a filter cigarette from the air outlet of the first passage member connected to the non-filter side end face of the cigarette, improving accuracy of the air pressure detection using the first pressure transducer. Thus, the cigarette quality can be judged with high accuracy.
More preferably, the pressure means includes a metal mouthpiece having an end face, which is formed into a flat face, for pressing the second end face of a filter cigarette and supported displaceably in an axial direction.
According to this preferred embodiment, it is possible to surely introduce air through the air outlet passage of the first passage member to the non-filter side end face of a filter cigarette while holding the filter cigarette between the first passage member and the mouthpiece, which improves the accuracy of the cigarette quality judgement. Moreover, a structure for holding the cigarette between the first passage member and the mouthpiece by axially displacing the mouthpiece is simple, making this cigarette inspection apparatus suitable for incorporation into the cigarette manufacturing apparatus. Furthermore, since a cigarette is pressed by the flat end face of the mouthpiece, there is only a little fear of damaging the cigarette.
Preferably, the cigarette inspection apparatus further comprises an inspection drum having a rotary shaft and a peripheral surface thereof formed, at intervals in a circumferential direction, with a plurality of cigarette holders for receiving the filter cigarettes dischargeably, and a first stationary member supported for sliding contact with the first passage member. The first passage member is formed of a ring member that is mounted on a peripheral edge portion of one side of the inspection drum so as to be rotatable in unison with the inspection drum. A plurality of air passages are formed in the first passage member at intervals in the circumferential direction so as to be alignable to the cigarette holders of the inspection drum in the axial direction. The first stationary member is formed with an air passage with which the plurality of air passages of the first passage member can communicate sequentially, and the first pressure transducer is connected to the air passage of the first stationary member.
According to this preferred embodiment, with rotation of the inspection drum and the first passage member mounted thereon, the air passages of the first passage member sequentially communicate with the air passage of the first stationary member. As a result, air can be introduced sequentially into the filter cigarettes received in the respective cigarette holders of the inspection drum through the air passage of the first stationary member and the corresponding air passage of the first passage member. At this moment, the individual cigarette is pressed toward the first passage member by the pressure means, and air is introduced into the cigarette without fail. Also, the air pressure on the first end face side, i.e., the non-filter side, of the cigarette is detected by the first pressure transducer. It is preferable that the air pressure is detected in the state where the peripheral surface of a cigarette is open to the atmosphere.
In the preferred cigarette inspection apparatus, the quality of the filter cigarettes received in the respective cigarette holders of the inspection drum is sequentially judged with the inspection drum rotated. The filter cigarette that has been judged in its quality is discharged from the cigarette holder, which enables a new filter cigarette to be received in the cigarette holder. Thus, the quality judgement can be performed efficiently with respect to a large number of filter cigarettes. Furthermore, the inspection drum can be utilized as a conveyance drum of the cigarette manufacturing apparatus, which facilitates incorporation of the cigarette inspection apparatus into the cigarette manufacturing apparatus. If necessary, the filter cigarettes manufactured by the cigarette manufacturing apparatus can be subjected to the 100% inspection.
According to the present invention, preferably, the air-introducing means comprises a first passage member having an air passage with an air outlet for discharging air supplied from an air source and disposed for abutment with a first end face of a filter cigarette, which is on the non-filter side of the cigarette, and pressure means for pressing the filter cigarette in the axial direction to make the first end face of the non-filter side thereof connected to the air outlet of the first passage member. The pressure means has a mouthpiece which can press a second end face of a filter cigarette, which is on the filter side of the cigarette, the mouthpiece being formed with an air passage having on one side thereof an opening end connectable to the second end face of the cigarette, and a second passage member for supporting the mouthpiece displaceably in the axial direction, the second passage member being formed with an air passage communicating with an opening end on another side of the air passage of the mouthpiece. The first and second pressure transducers are connected to the air passage of the first passage member and the air passage of the second passage member, respectively.
According to this preferred embodiment, it is possible to introduce air into a filter cigarette without fail and to surely detect the air pressures on the first and second end face sides of the cigarette, respectively, in a state where the filter cigarette is held between the first passage member and the mouthpiece.
More preferably, the cigarette inspection apparatus further comprises an inspection drum having a rotary shaft and a peripheral surface thereof formed, at intervals in the circumferential direction, with cigarette holders for receiving filter cigarettes dischargeably, and first and second stationary members supported for sliding contact with the first and second passage members, respectively. The first and second passage members are formed of ring members that are mounted on peripheral edge portions of both sides of the inspection drum, respectively, so as to be rotatable in unison with the inspection drum. Air passages are formed in the first passage member at intervals in the circumferential direction so as to be alignable to the cigarette holders of the inspection drum in the axial direction. The second passage member supports a plurality of mouthpieces displaceably in the axial direction, the mouthpieces being formed with air passages that are alignable to the cigarette holders of the inspection drum in the axial direction, respectively. The second passage member is formed with a plurality of air passages communicating with the respective air passages of the mouthpieces. The first stationary member is formed with an air passage with which the air passages of the first passage member can communicate sequentially, whereas the second stationary member is formed with an air passage with which the air passages of the second passage member can communicate sequentially. The first and second pressure transducers are connected to the air passage of the first stationary member and that of the second stationary member, respectively.
According to this preferred embodiment, with rotation of the inspection drum and the first and second passage members mounted thereon, the air passages of the first passage member sequentially communicate with the air passage of the first stationary member, and the air passages of the mouthpieces communicate with the air passage of the second stationary member one after another through the respective air passages of the second passage member. Accordingly, air can be sequentially introduced into the filter cigarettes received in the respective cigarette holders of the inspection drum through the air passage of the first stationary member and the corresponding air passage of the first passage member. Also, the air pressures on the first and second end face sides of the cigarette can be individually detected without fail. Thus, judgement on the quality of a large number of cigarettes can be efficiently performed. Moreover, the use of the inspection drum as a conveyance drum of the cigarette manufacturing apparatus facilitates the incorporation of the cigarette inspection apparatus into the cigarette manufacturing apparatus. It is also possible to subject the filter cigarettes manufactured by the cigarette manufacturing apparatus to the 100% inspection.
Preferably, the cigarette inspection apparatus detects the air pressure produced on the first end face of the non-filter side of a filter cigarette by the first pressure transducer in a state where the peripheral surface of the cigarette is open to the atmosphere and the air introduced into the cigarette is prohibited from flowing out from the second end face of the filter side of the cigarette.
According to this preferred embodiment, the pressure drop in the cigarette can be detected with high precision, based on the air pressures detected before and at the time of introducing air, respectively, and the cigarette quality can be accurately judged.
Preferably, the cigarette inspection apparatus detects the air pressures produced on the first end face of the non-filter side of a filter cigarette and on the second end face of the filter side thereof by the first and second pressure transducers, respectively, in the state where the peripheral surface of the cigarette is open to the atmosphere and the air introduced into the cigarette is prohibited from flowing out from the second end face of the filter side of the cigarette.
According to this preferred embodiment, the pressure drop in the cigarette can be detected with high precision, based on the difference between the air pressures produced on both end faces of the cigarette, respectively, and the cigarette quality can be accurately judged.
In case of the cigarette inspection apparatus designed to permit the air passages of the second passage member, communicating with the respective air passages of the mouthpieces, to communicate sequentially with the air passage of the second stationary member, it is preferable that the air passage of the second stationary member has an opening only on the second passage member side of the second stationary member.
According to this preferred embodiment, in a state where the mouthpiece is in contact with the second end face of a cigarette, air passages, corresponding to the cigarette, of the mouthpiece, the second passage member and the second stationary member define a closed space as a whole, thus preventing air from flowing out from the second end face of the cigarette.
Preferably, the quality-judging means subjects output of the first pressure transducer to filtering to remove a noise component, and determines, at a predetermined measurement timing, the air pressure on the first end side of the filter cigarette, based on the filtered output.
According to this preferred embodiment, it is possible to remove an external noise superposed on the output of the first pressure transducer, such as for example, a noise component, especially a high frequency noise component, mingled during the cigarette manufacturing process. Therefore, the air pressure can be detected with precision.
In the cigarette inspection apparatus comprising the first and second pressure transducers, it is preferable that the measuring means subjects outputs of the first and second pressure transducers to filtering to remove noise components, determines a difference between the two filtered outputs at a predetermined measurement timing, and determines the ventilation resistance of a filter cigarette, based on the difference between the filtered outputs.
According to this preferred embodiment, it is possible to remove external noises superposed on the outputs of the first and second pressure transducers and to obtain the ventilation resistance of the cigarette with great accuracy, based on the difference between the two outputs.
The cigarette inspection apparatus comprising the first and second pressure transducers preferably further comprises an inspection drum having a peripheral surface thereof formed with cigarette holders for holding filter cigarettes. The air-introducing means sequentially introduces air into filter cigarettes that are carried one by one to an inspection position according to rotation of the inspection drum. The first and second pressure transducers sequentially detect the air pressures on the first and second end sides of the filter cigarettes into each of which air is introduced when the individual cigarette is at the inspection position. The measuring means sequentially determines the ventilation resistances of the filter cigarettes into each of which air is introduced when the individual cigarette is at the inspection position. The quality-judging means comprises measured data-classifying means for classifying the ventilation resistances of filter cigarettes, which have sequentially been determined by the measuring means, so that the ventilation resistances of each cigarette correspond to the cigarette holder with which that cigarette has been held, and evaluating means for evaluating a cigarette-holding characteristic of each cigarette holder, based on a characteristic indicated by a set of the ventilation resistances corresponding to that cigarette holder.
According to this preferred embodiment, it is possible to precisely grasp an effect of each cigarette holder upon the ventilation resistances of filter cigarettes, more particularly a cigarette-holding characteristic of each cigarette holder, based on the characteristic indicated by the set of the ventilation resistances classified to correspond to that cigarette holder. In the present invention, it is desired to detect the air pressure produced on the end faces of a filter cigarette due to the air introduction into the filter cigarette in the state where the peripheral surface of the cigarette is open to the atmosphere, and the introduced air is prohibited from flowing out from the filter side end face of the cigarette. It is also desired that air should be properly introduced from the non-filter side end face of the cigarette. The cigarette-holding characteristic of each cigarette holder of the inspection drum is closely associated with such conditions. If the cigarette-holding characteristic of any one of the cigarette holders is declined, the accuracy of the cigarette quality judgement on the basis of the air pressure is deteriorated, which produces fear of inducing a misjudgment. In this point, the cigarette inspection apparatus according to the preferred embodiment is designed to grasp the cigarette-holding characteristic of each cigarette holder with accuracy. This makes it possible to detect immediately the cigarette holder whose cigarette-holding characteristic is deteriorated to suggest maintenance thereof and to reject a result of the cigarette quality judgement in respect of such cigarette holder to avert the misjudgment.
More preferably, the evaluating means determines dispersion or a mean value of the ventilation resistances corresponding to the individual cigarette holder, as the characteristic indicated by the set of the ventilation resistances.
According to this preferred embodiment, it is possible to obtain accurately the characteristic indicated by the set of the ventilation resistances corresponding to the individual cigarette holder.
Preferably, the evaluating means provides a graphical representation of the characteristics, indicated by those sets of the ventilation resistances which correspond to the cigarette holders, in which representation the characteristics are arranged in an order the cigarette holders are guided to the inspection position according to the rotation of the inspection drum.
With this preferred embodiment, the characteristics indicated by the sets of the ventilation resistances corresponding to the respective cigarette holders can be easily compared with one another, based on the graphical representation.
Preferably, the evaluating means comprises malfunction-detecting means for detecting the cigarette holder whose cigarette-holding characteristic is deteriorated, based on the characteristics indicated by the sets of the ventilation resistances corresponding to the respective cigarette holders.
According to this preferred embodiment, the cigarette holder whose cigarette-holding characteristic is deteriorated can be accurately detected to suggest the maintenance thereof, thus averting a misjudgment on the cigarette quality.